Page 145 - Computer_Science_F5

Computer Science Aim: 1. Discuss the factors affecting signal
Activity 3.2:
Exploring of the Physical Layer
FOR ONLINE READING ONLY
Understand the physical layer of the
OSI model and its role in network
communication.
Materials:
1. Computer with Internet access
2. Access to online resources or
library
Instructions:
Use Internet search, perform the
following:
1. Research the Physical Layer: Use
the Internet to explore and analyse
the physical layer of the OSI model. enabling the activation, maintenance,
2. Identify Transmission Medium:
Determine the type of transmission
medium used to connect your
computer to the network.
3. Classify Transmission Medium:
Identify the broad category of
this transmission medium (such
as, wired, wireless) and list its
advantages and disadvantages.
4. Analyse data transmission: Discuss
how this transmission medium
sends and receives bits for website
viewing on your computer.
Deliverables:
A written report detailing your analysis
of the physical layer, the type of
transmission medium used, its category,
advantages and disadvantages, and an
explanation of how it facilitates data
transmission.
Finally, document your findings in a
portifolio.
136
Computer Science Form 5.indd 136
Exercise 3.3
strength at physical layer
the physical layer
2. What are the main devices used at
3. Discuss how the physical layer’s
design and implementation
influence the efficiency and
reliability of a network.
Data link layer
While the physical layer only provides
a basic service of transmitting raw bits,
the data link layer aims to enhance the
reliability of the physical link while
and deactivation of the link. The data
link layer is responsible for the physical
transmission of data and performs
various tasks such as error notification
(error detection) through ACK/NACK,
managing network topology (logical
topology), and handling flow control to
prevent buffer overflow issues. With a
fully functional data link layer protocol,
the higher layer can assume that
transmission over the link is error-free.
The data link layer ensures that messages
are delivered to the correct device on a
local area network (LAN) using hardware
addresses. It also translates messages
from the network layer into bits for
transmission by the physical layer. The
data link layer breaks down the message
into smaller units called data frames and
adds a customized header that includes
the hardware destination and source
addresses. The data link layer consists
for Advanced Secondary Schools
23/07/2024 12:33